With the recent greatly accelerated growth in the procedures and applications involving competitive binding techniques, especially radioimmunoassay (hereinafter "RIA"), for medical diagnostic work and research, the need for greater processing volume and reliability, along with decreased labor and handling has become increasingly acute. In particular, the problem of avoiding the handling of individual samples has been a particularly difficult one to solve. The desire for greater automation, but in a manner which will decrease chances of error, expand technician capacity, and maximize the number of samples processed in a given amount of time is still a largely unfulfilled one.
As is well known, competitive binding techniques involve various steps to be performed with a multiplicity of samples, incuding the positioning of sample vials or tubes in an array, and labelling or otherwise identifying each, preparation of the samples, i.e. adding reagents and tracers, as well as diluting, replicating and the like, mixing, incubation, separation of the bound and unbound phases, and, in RIA, counting the radioactivity of each. Of course, this multiplicity of samples must be transported between the stations at which each of the above steps is to be performed, and some means of resting the samples between stations is necessary.
Much attention has been devoted to improvements of apparatus performing parts of the above procedure, but little attention or success has been given to improvements pertinent to the elements common to all of the foregoing steps. Accordingly, even improvements at one of the stations or steps have not been very valuable from the viewpoint of improving the entire procedure. For example, automated sample preparation equipment of various kinds has become available in recent years to shorten the work of the sample preparation step. However, the benefits of such equipment often are largely discounted, since typically extra effort must then be expended to identify the various tubes emerging from the equipment, as well as to thereafter individually load and unload tubes into mixing or vortexing equipment for many procedures, or other apparatus used in subsequent steps. Typically, the assembly which supports the sample during preparation, or some other subsequent step, is not compatible with one or more of the devices used in the other steps of the protocol. Furthermore, at some point in the procedure, separation between bound and unbound phases typically will be made, and this will usually involve decanting, another step which usually must be done on an individual sample basis.
Likewise, high throughput gamma counters have recently appeared with programmable operation, fast electronics and data processing equipment. But again, the efficiency advantages of such equipment are largely discounted, as is the case with improvements applicable to the earlier steps, because of the need to handle samples on an individual basis, or because of incompatibility with the preceding sample handling. Equally important, even without the foregoing problems, the counter typically cannot process more than one sample at a time, thus presenting an inherent efficiency bottleneck even without the foregoing problems.
More recently, with the invention of the apparatus disclosed in the commonly assigned co-pending application entitled, "Radioactivity Measuring Device with a Movable Detector Head", Ser. No. 366,676, filed June 27, 1973, as a continuation of application Ser. No. 273,768, filed July 21, 1973, a counter has been invented which would count more than one sample at a time. Known sample support or sample tray assemblies generally in use would certainly not be compatible with such apparatus. In particular, a sample support assembly has not heretofore been disclosed which is capable of cooperating properly with such an apparatus while enabling simplified processing without individual sample handling at earlier stages of the procedures. No improvement has yet to appear which would obviate the common drawbacks cited above, and enable a true improvement in the overall efficiency and simplicity of the entire process, particularly when simultaneously processing a multiplicity of samples.